The first objective of this proposal is to characterize the firing patterns of hippocampal neurons associated with the disambiguation of memories for overlapping sequences of events, a critical feature of episodic memory. Single neuron activity and local field potentials in the CA1 and CAS regions will be recorded as rats perform a sequence disambiguation task. The relationships between the timing of spiking activity, phase of field potentials, and behavioral events will be analyzed to test specific predictions made from computational models. The second objective is to design a computational model that will incorporate these new findings to provide a detailed description of the neuronal mechanisms underlying sequence disambiguation, and to generate novel predictions for further analysis. The simulations will be constrained by the anatomy and physiology of the hippocampal region, and replicate the dimensions of the behavioral task. These results will add to our understanding of the mechanisms of hippocampal involvement in memory and consequently are fundamental to the study of disorders associated with dysfunction of the hippocampal system such as age-related memory disorder, Alzheimer's disease, schizophrenia, and autism. [unreadable] [unreadable] [unreadable]